Ptychogena californica is a hydrozoan medusa (family Ptychogeniidae) found in cold temperate and subarctic waters of the northeastern Pacific coast, a relatively delicate transparent medusa with a characteristic folded bell and marginal tentacles used for prey capture in nearshore and coastal oceanic environments. As with many hydromedusae, its benthic hydroid stage is poorly characterized, and genomic data may facilitate identification of its life cycle stages in environmental samples.